Comparison of different energy storage systems for renewable energies on a Caribbean island

The Caribbean has a great technological and economic potential for using renewable energies for power generation based on the natural conditions. In case of generation from fluctuating sources such as solar and wind, the storage of excess electricity is necessary to cover periods of insufficient power generation. To decrease the share of diesel GenSets in the energy supply system more renewable energy and storage capacity is needed. The task of our study is to find the techno-economic optimized energy supply system including energy storage systems. Here we analyze the small Caribbean island Petite Martinique (1000 inhabitants), Grenada. Sealed lead-acid batteries are compared to vanadium redox flow batteries in different combinations with photovoltaics and wind turbines. Due to the hot climate a cooled environment has to be considered for the lead-acid batteries. Finally three scenarios are compared for different configurations of storage in the energy supply system: lead-acid batteries with lifetime of 5 years, with lifetime of 10 years and vanadium redox flow batteries. The best scenario for different shares of renewable energies in the energy supply system is shown.